At 15.5mm (0.61 inches), the E-TEN X500 is the thinnest Windows Mobile Pocket PC edition phone so far, from any company. The phone runs on a 400MHz Samsung processor, has EDGE, 802.11b/g, GPS support, a 2-megapixel camera, and Bluetooth 2.0. There's no slide-out keyboard, unfortunately, so that puts this phone in the same category as the HTC Artemis. No pricing yet, but the X500 should be out in November.
Thinnest E-TEN Pocket PC Phone Coming Soon - X500 [Mobility Site]